The importance of a display device has increased with the development of multimedia. In this respect, various types of display devices, such as a liquid crystal display (LCD) and an organic electroluminescent display device, have been used.
An LCD is a device for applying an electric field to a liquid crystal material having dielectric anisotropy, which is injected between two substrates, and adjusting the amount of light passing through the substrate from an external light source by adjusting an intensity of the electric field to obtain a desired image signal.
In general, an organic electroluminescent display device, which is a display device for emitting light by electrically exciting a fluorescent organic compound, may display an image by voltage programming or current programming a plurality of organic light emitting diodes (OLEDs) arranged in a matrix form. Methods of driving an organic electroluminescent display device include a passive matrix method and an active matrix method that uses a thin film transistor. While the passive matrix uses an anode and cathode orthogonal to each other and selects a line to drive the organic electroluminescent display device, the active matrix method connects a thin film transistor to each indium tin oxide (ITO) pixel electrode, and drives the organic electroluminescent display device using a voltage maintained by a capacitor capacity connected to a gate of the thin film transistor.
The aforementioned display devices generally include horizontally disposed gate lines and vertically disposed data lines in a display panel, and pixels are disposed in areas where the gate lines and the data lines cross and form a matrix array.